The present invention is directed to a shock wave head for non-contacting disintegration of a calculus situated in the body of a life form. The shock wave head includes a shock wave generator for generating a shock wave in essentially one plane and a lens arrangement which is for focussing the shock wave onto a region of focus in a target region. Shock wave heads of this type are utilized in medicine, for example for destroying stones in the kidneys of a human. Since they avoid any and all entry into the body, they are especially advantageous and do not require the need of surgery.
A shock wave head, which comprises a shock wave tube composed of a jacket, of a shockwave generator having a flat coil and a copper membrane separated by an insulating foil, is disclosed in U.S. Pat. No. 4,674,505, whose disclosure is incorporated by reference and which claims priority from German Patent Application No. 33 28 051. In this device, an acoustical positive lens was adjustably arranged in the shock wave tube, and this lens focussed the planar shock wave generated by the membrane into a focal point. For the purpose of coupling the shock wave tube to the patient, the opening of the shock wave tube lying opposite the membrane is closed with a flexible sack or bag which, like the entire shock wave tube, is filled with a coupling agent. For coupling, the shock wave tube is moved in the direction towards the patient until the calculus to be destroyed is situated in the focal point of the lens arrangement. The bag or sack filled with the coupling fluid is placed against the surface of the patient so that it is guaranteed that the shock wave always proceeds within the coupling fluid until it enters the body.
With an obese patient, problems have occurred because the calculus to be destroyed lies so far inside the body of the patient that the focal distance of the lens arrangement is no longer adequate. As a result of this problem in a coupling procedure, the shock wave tube or, respectively, the lens arrangement contacts the patient and even pushes a portion of the patient aside or out of the way, given continuation of the coupling procedure. As a result thereof, the calculus is often moved out of an in-focus range or region so that a treatment can no longer be carried out.